Validation of a novel forensic method

[Audio] Validation of a novel forensic method Analysis of “of the Ver plex blood identification System” Amanda wise Ethical principles in forensic science 1/8/2026.

[Audio] Ensure: For Scientific Evidence that Method/Instrument is Fit-for-Purpose in Forensic Application Reproducibility (operator, time, instrument). Accuracy & Precision (under specified conditions). Robustness (varied sample types and conditions) Supports Accreditations (e.g. ISO/IEC 17025) - ensures integrity, admissibility, reliability of evidences in court.

[Audio] Title: The VeriPlex™ Blood ID System: What is it? Problem: Catalytic tests for blood (e.g., Kastle-Meyer) lack human specificity, and can be falsely reactive. Solution: The Veri Plex™ System - rapid, immunochromatographic assay. Steps: Extract antigen from stain. Include antibodies to human hemoglobin. Yield visible result on test strip (like a pregnancy test). Image source: Microsoft 365 content library Science is the systematic study of the natural world through observation and experimentation. It helps us understand phenomena, develop new technologies, and solve complex problems. Scientific inquiry fosters critical thinking, encourages innovation, and drives advancements that benefit society and improve our quality of life..

[Audio] The validation framework: What was tested? Study followed a structured approach based on scientific working group on DNA Analysis methods guidelines. Key validation Parametres Tested: Sensitivity/ Dynamic Range: Minimum sample quantity and detection limits. Specificity: cross- reactivity with non-human blood, common interferents, and other body fluids. Reproducibility & Precision: Consistency across multiple operators, lots, and instruments Robustness: Performance under varied conditions (temperature, humidity). Case-type samples: performance on realistic, aged and compromised samples Image source: Microsoft 365 content library Forensics applies scientific principles to solve crimes and analyze evidence. Techniques such as DNA analysis, fingerprint identification, and digital forensics help identify suspects and reconstruct crime scenes. Forensic experts play a crucial role in criminal investigations, ensuring evidence is accurately collected, preserved, and presented in court..

[Audio] core performance sensitivity & Specificity Efectively Identifies human blood dilution down To 1:100,000 Only a 0.5mm diameter stain needed (very small sample). 0.5mm Why its important: Establishes limits of detection of trace evidence. Specificity findings: No cross-reactivity with animal bloods(dog,cat,horse,cow,pig,deer) No reaction with saliva, semen, urine or common interferents (rust, coffee, bleach) Why its important: targets weakness of presumptive tests; very low false postives.

[Audio] Reproducibility & Robustness Reproducibility: 100% concordance across three different instrument lots*. 100% concordance across multiple operators*. Importance: Demonstrates method is operator-independent and manufacture is consistent—key for quality control. Robustness: Reliable results across a range of* laboratory temperatures and humidity levels*. Importance: Proves the method is stable under normal lab variations, ensuring reliability day-to-day..

[Audio] The Real-World Test: Case-Type Samples ​ Samples tested included: * Aged stains (up to one year old). Stains on *various substrates** (denim, carpet, wood, glass). * Environmentally exposed samples (UV light, heat, humidity). * Mixtures (blood with soil, detergent). * Results: System performed reliably on most substrates and aged samples. * Key Finding: Some false negatives occurred on heavily dyed fabrics (e.g., black denim). * Importance: Identifies limitations and boundaries of the method for real-world application.

[Audio] Analysis: Strengths of the Validation Study 01 ✔ Comprehensive: ALL core SWGDRAM parameters 02 ✔ Ecologically Valid: REAL “case-type” samples, not just clean controls 03 ✔ Openly reported a CRUCIAL limitation (false negatives on dyed fabric) 04 ✔ Followed rules of forensic validation (eg SWGDAM) 05 ✔ Scientifically valid: replicates, multiple operators for precision data.

[Audio] Analysis: Identified Gaps & Recommendations * ⚠ Gap 1 - Inhibitor Studies: Dye interference was observed but not systematically characterized. No experiments with a range of known dyes with inhibitory properties. * Recommendation: A dedicated study to identify map inhibitory substances - develop “don’t use” or “use cautiously” list * ⚠ Gap 2 - Quantitative Threshold: No studies on what counts as a “faint positive”. Subjective nature of interpreting faint lines may vary. * Recommendation: Define objective criteria (e.g., reader instrument) or have a firm protocol for interpreting weak results * ⚠ Gap 3 - Extended Mixtures: Blood with other mixtures ?(e.g. paints, oils, other bodily fluids mixed with blood).

[Audio] Conclusion and Implications for the Lab The validation study *proved beyond a doubt** that the Veri Plex system is a robust, specific, and sensitive method for blood identification in human samples It establishes the *gold standard** for how a forensic lab should conduct its own internal validation before the system can be deployed * Take Home Message: It’s an excellent protocol blueprint, but it also shows that sometimes, validation reveals limitations which must be addressed in the lab's SOP. * Final Thoughts: Good validation, as done here, turns a promising new tool into an admissible tool for forensic scientists in court.

[Audio] References * Roelofse, M. M., Steers, N. J., Fistonich, M. L., & Bishop, L. A. (2019). Validation of the VeriPlex™ Blood Identification System for the forensic identification of human blood. *Forensic Science International: Genetics Supplement Series*, 7(1), 845-847. [Link or DOI would be included] * Scientific Working Group on DNA Analysis Methods (SWGDAM). (2016). *Validation Guidelines for DNA Analysis Methods*. * ISO/IEC 17025:2017. *General requirements for the competence of testing and calibration laboratories*..